14 Mar
2007
14 Mar
'07
11:25 a.m.
On 3/14/07, Chuck Guzis <cclist at sydex.com> wrote:
On 14 Mar 2007 at 12:32, Ethan Dicks wrote:
I've certainly torn apart many embedded devices to see how they
worked, to see if they could be hacked, to dump ROMs, etc.
Unfortunately, thinking about modern devices, they seem to have
epoxy-potted bare dice and no external ROMs. One recent case in point
- an LED messager I picked up at the Mansfield Hamfest for $2... it
has a grid of 7x21 discrete LEDs, a few TTL chips, some row/column
driver transistors, and a mysterious controller under an epoxy blob.
As shipped, you can feed this thing a message (via input buttons) and
have the message scroll across the LEDs. It also has a built-in clock
AM/PM clock mode. Personally, I'd prefer 24-hour time, or the ability
to feed this thing messages from a machine on the network. Well...
long story short, after tearing it down, I decided to put it back
together. I can get four 7x5 LED blocks for a few dollars and hook
them up to a microcontroller and it will do exactly what I want, and I
don't have to invest the time to reverse-engineer somebody else's
design first.
I do, however, spend time reverse-engineering peripherals to adapt
them to different platforms (POS "Pole Displays", Dragon's Lair/Space
Ace LED scoreboard, DSR-4400 satellite decoder box LCD/LED/button
interface board...) _Those_ items can be hooked to a variety of
machines, and especially to whatever my development box/daily drive
happens to be. It doesn't matter what processor these came from - a
peripheral is still a peripheral and does the same task 5, 10, or 20
years later, even when processors and operating systems are vastly
different.
So while I might not turn down a box of embedded
devices like a credit
card terminal, hacking a lone terminal isn't as appealing as building
a similar device from scratch and knowing exactly how that new device
works.
I suppose I can appreciate your viewpoint. Digging into little
gizmos, even if it's to dump the ROMs is more appealing to my inner 5-
year old. My parents could never give me anything mechanical
or
electrical without having me take it to pieces.
That was my childhood as well - I tore apart many telephones, radios,
and televisions growing up. I also remember when my Dad gave me a
toolbox and a sewing machine - that thing took 2 days to dismantle.
Lots of tiny screws and springs. Electronic stuff was more
fascinating, so here I am.
-ethan